Iodine is one of the essential nutrients, iodine tincture has been used as disinfectant for a long history. Iodine has also been used as a particularly-effective medicament for the treatment of goiter. However, the main disadvantage of iodine is that it can be sublimated easily, and thus is unstable. To prepare stable iodine, Germany Patent DE-2941387 and DE-3060935 provide polyvinyl pyrrolidone-iodine (PVP-I), which is a kind of complex wherein PVP is complex reagent. The stability of PVP-I is better than iodine, but said complex reagent PVP is not required to animals. The iodine complex prepared by quaternary ammonium salt has the same defect.
Vinod Singh and Ram Sahai(Monatshe fur Chemie 117, 345–350, 1986) had investigated the charge transfer between several amino-acids, e.g phenylalanine, alanine, tryptophan and iodine, they considered that the charge transfer complex has been formed as the result. Rafie H. et al. (Zeitschrift fur Physikalische Chemie, BD. 178, 67–86, 1992) had investigated the process of forming the charge transfer complex between histidine, tryptophan and iodine dissolved in the solution potassium iodide, found that the pH value remains unchanged during the process, and the process only involves the amino group of the amino-acid, but not the carboxyl group. Electrode material disclosed in JP 63143750 is also a kind of charge transfer complex formed between amino-acid and iodine. The common characteristic of the above mentioned materials is that the complex, which is a kind of ionic triiodide-complex of amino-acid, was formed by reaction of ionic triiodide-complex (I−3) as reactant in which iodine as electronic acceptor, with the amino group of amino-acid as electronic donor. If the amino-acid is in excess, fading would occur and the iodine will lose the activity of disinfection. The introduction of iodic ion (I−) in large amount produces no favorable effect on the activity of disinfection, but increases the cost of manufacture.
The objective of the present invention, aimed at the defects of prior art, is to provide an iodine complex wherein the iodine is stable, the complex reagent can also be a nutrient, and iodine molecule can directly react with amino-acid without adding an iodic ion. It is also the objective of the present invention to provide a process for the production of said complex.
It is now discovered that the amino-acid and iodine are the dialectic system, amino-acid being not only the electronic donor, but also the electronic acceptor; iodine being the electronic acceptor, and electronic donor as well. Iodine is a non-metal, but it possesses some characteristics of a metal. An amino-acid is a complex reagent, and a nutrient too. Amino-acids are natural material, so when they are used as complex reagent, they can increase the ability of disinfection through the metabolism of organism. Both the amino group and the carboxyl group of an amino-acid can combine with iodine molecule simultaneously under suitable conditions such as temperature, solvent and catalyst etc. to form a stable amino-acid iodine complex, viz. amino-acid amino-carboxyl iodine complex.